17M.1.AHL.TZ1.H_1

* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.

${\log }_{2}x-{\log }_{2}5=2+{\log }_{2}3$

collecting at least two log terms     (M1)

eg$$${\log }_2\frac{x}{5}=2+{\log }_{2}3\text{ or }{\log }_2\frac{x}{15}=2$

obtaining a correct equation without logs     (M1)

eg$$$\frac{x}{5}=12$$$OR$$$\frac{x}{15}=2^2$     (A1)

$x=60$     A1

[4 marks]

[N/A]